Lifting jack



Patented Aug. 6, 1929.

ARTHUR C. HOPKINS, OF MILES, iiltllri A l, AFISEGIEIOR TO NATIONAL-STANDARD COIMPAIZY, 0 I/IIOHIGAN.

LIFTING JACK.

Application filed May 18, 1927. Serial No. 132,28.

The main objects of this invention are to provide an improved lilting jack which is compact when collapsed and which may be extended to a considerable height.

A further object is to provide an improved lifting jack which poweriful and at the same time is simple and compact in structure.

Objects relating to details and economies of construction and operation of my invention will appear from the detailed .lescription to follow.

The invention. is defined and pointed out in the claim.

A structure which is a preferred embodiment of my invention is illustrated in the accompanying drawing, forming a part of this application, in which:

Fig. l is a detail View of my improved lifting jack on a line corresponding to line 1-1 of Fig. 2. A

Fig. 2 is a fragmentary horizontal section on a line corresponding to line 2-2 of Fig. 1. v

Fig. 3 is a side View of my improved jack partially extended, parts being broken away to show structural details.

The embodiment of my invention illustrated in the accompanying drawing comprises a hollow standard 1 provided with a base 2. At the top of the standard is a bracket 3, the top portion of the bracket being disposed in spaced relation to the top of the standard and having an openingsl therein aligned with the bore of the standard.

The lifting member or lifting bar comprises a tubular bottom section 5 adapted to telescope within the standard and a top section 6 telescoping within the bottom section.

The bottom section 5 of the lifting memher is provided with a top 7 having an opening 8 therein through which the top section slides.

The top section has a foot portion 9 at its lower end slidablyfitting within the bottom section so that these parts are held in alignment for free telescoping movement.

The bottom section is of cylindrical cross section and is externally threaded. Its rotation, however, is prevented by the pin 10 coacting with the vertical groove 11 in the standard.

The driving nut 12 is rotatably supported within the bracket upon a thrust bearing designated generally by the numeral 13 mounted on the end of the standard. This driving nut is provided with a beveled gear lei with which the driving gear 15 coacts, the driving gear being journaled at 16 on the extension ll of the bracket to receive the shaftof a crank 18.

The section 5 being held against rotation, it is raised and lowered within the standard by the rotation of the nut.

The top section (5 is, in the embodimen illustrated, of channel cross section to receive the linked cable or chain 19, one end of which is connected to the top lifting member section 6 at 20, the other end of the cable being comiected at 21 to the upwardlyprojectlng ears on the standard. This cable is passed over a roller 23 mounted on the bottom lifting member, or in other words, the roller engages the bight of the cable between its ends so that as the bottom lifting member is raised by its screw actuating means, the top lifting member is projected at the same time.

By forming the top lifting member of channel cross section, it is adapted to re eeive the cable when the jack is collapsed, as shown in Fig. 1.

The top lifting member is provided with a suitable head 2%.

The links of the cable preferably have curved edges 25 corresponding to the curvature of the roller so that the cable passes balloon tires and for storage or transporta- Within said bracket to coact with said bottom 0 lifting member sectioinsaid nut being provided with a beveled gear, and a driving gear mounted on said standard to coact with said on said nut.

In Witness whereof I have hereunto set 15 my hand.

ARTHUR C. HOPKINS. 

